Whose stock is more profitable, in your opinion: Alibaba's or Amazon's?

Both of them are probably pretty good investments, but these are very well studied companies and all the currently available information on them is already built into the stock price, so I doubt either is undervalued. You will hear stories about people who bought the right stock at the right time and made a fortune. What you won't hear about are the people who bought the wrong stock and lost out. When buying stocks as an independent investor, you will likely get the best results by buying a basket of decent quality stocks across a number of industries. It's not particularly glorious, but it yields the highest yield for the lowest risk.

No matter what stock you choose to invest in, make sure you do deep research before investing in any stocks. The stock market has shown large ups and downs due to various factors like trade war, Brexit, etc which has shaken the global economy and market. As per current stock market news, the current stocks globally ahs shown fluctuating graph recently.